Cross-blockchain interaction systems

ABSTRACT

One or more embodiments of the present specification provides cross-blockchain interaction systems. One system includes: one or more anchor devices, wherein at least one of the one or more anchor devices comprises a first client terminal associated with a first blockchain network, and wherein the first client terminal is configured to monitor cross-blockchain requests sent from the first blockchain network; and one or more relay devices, wherein at least one of the one or more relay devices comprises a second client terminal associated with a second blockchain network that monitors cross-blockchain requests intended for the second blockchain network.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims the benefit of priorityof U.S. patent application Ser. No. 17/163,348, filed on Jan. 30, 2021,which is a continuation of PCT Application No. PCT/CN2019/106610, filedon Sep. 19, 2019, which claims priority to Chinese Patent ApplicationNo. 201811364463.0, filed on Nov. 16, 2018, and each application ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

One or more embodiments of the present specification relate to the fieldof blockchain technologies, and in particular, to cross-blockchaininteraction systems.

BACKGROUND

In related technologies, cross-blockchain interaction between differentblockchains can be implemented by using a relay chain. The relay chaincan be connected to each blockchain. Several validators provided on therelay chain verify cross-blockchain data on each blockchain by usingconsensus algorithms, and other blockchains can obtain thecross-blockchain data provided that the blockchains are connected to therelay chain.

SUMMARY

In view of this, one or more embodiments of the present specificationprovide cross-blockchain interaction systems.

To achieve the previous objective, one or more embodiments of thepresent specification provide the following technical solutions:

According to one or more embodiments of the present specification, across-blockchain interaction system is proposed, including: one or moreanchors, where when any anchor is selected by a first blockchain, theany anchor is configured with a client device of the first blockchain soas to monitor a cross-blockchain request on the first blockchain; andone or more relays, where when any relay is selected by a secondblockchain, the any relay is configured with a client device of thesecond blockchain; and when a request object of the cross-blockchainrequest is the second blockchain, the any relay initiates a request tothe second blockchain based on the cross-blockchain request and receivesresponse data and a blockchain attestation that are returned by thesecond blockchain, so that the any relay verifies the response databased on the blockchain attestation and the any relay generates acorresponding relay attestation based on a configured trustedattestation conversion technology after the verification is passed, sothat the response data and the relay attestation are returned to thefirst blockchain through the any anchor.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating cross-blockchain interaction,according to an example embodiment;

FIG. 2 is a schematic structural diagram illustrating a cross-blockchaininteraction system, according to an example embodiment;

FIG. 3 is a schematic structural diagram illustrating anothercross-blockchain interaction system, according to an example embodiment;

FIG. 4 is a schematic structural diagram illustrating still anothercross-blockchain interaction system, according to an example embodiment;and

FIG. 5 is a schematic structural diagram illustrating a cross-blockchaininteraction system that provides a bridging function, according to anexample embodiment.

DETAILED DESCRIPTION

Example embodiments are described in detail here, and examples of theexample embodiments are presented in the accompanying drawings. When thefollowing description relates to the accompanying drawings, unlessspecified otherwise, same numbers in different accompanying drawingsrepresent same or similar elements. Implementations described in thefollowing example embodiments do not represent all implementationsconsistent with one or more embodiments of the present specification. Onthe contrary, the implementations are only examples of apparatuses andmethods that are described in the appended claims in detail and that areconsistent with some aspects of one or more embodiments of the presentspecification.

It is worthwhile to note that in other embodiments, steps of acorresponding method do not necessarily need to be performed in asequence illustrated and described in the present specification. Methodsin some other embodiments can include more or fewer steps than themethods described in the present specification. In addition, a singlestep described in the present specification may be divided into multiplesteps for description in other embodiments, and multiple steps describedin the present specification may alternatively be combined into a singlestep for description in other embodiments.

FIG. 1 is a schematic diagram illustrating cross-blockchain interactionaccording to an example embodiment. Cross-blockchain interaction betweenblockchain 1 and blockchain 2 shown in FIG. 1 is used as an example.Blockchain 1 and blockchain 2 can implement cross-blockchain interactionby using a cross-blockchain interaction system. The cross-blockchaininteraction system can include a trusted anchor and a trustedattestation conversion relay. The trusted anchor can be configured witha client device of blockchain 1 so as to establish a connection betweenthe trusted anchor and blockchain 1. The trusted attestation conversionrelay can be configured with a client device of blockchain 2 so as toestablish a connection between the trusted attestation conversion relayand blockchain 2.

In some embodiments, the client devices configured on the trusted anchorand the trusted attestation conversion relay can be simplified paymentverification (SPV) client devices, to implement lightweightconfiguration of the trusted anchor and the trusted attestationconversion relay. Related cross-blockchain interaction functions canalso be implemented by configuring other types of client devices.Implementations are not limited in the present specification.

In some embodiments, when blockchain 1 needs to retrievecross-blockchain data from blockchain 2, a cross-blockchain request canbe created on blockchain 1, and a request object of the cross-blockchainrequest is blockchain 2. The trusted anchor can monitor, by using theconfigured client device of blockchain 1, the cross-blockchain requestcreated on blockchain 1, and transfer the cross-blockchain request tothe trusted attestation conversion relay based on the fact that therequest object indicated by the cross-blockchain request is blockchain 2and a connection relationship between blockchain 2 and the trustedattestation conversion relay. The trusted attestation conversion relayfurther transfers the cross-blockchain request to blockchain 2.

Further, the trusted attestation conversion relay can retrieve, by usingthe configured client device of blockchain 2, response data generated byblockchain 2 in response to the cross-blockchain request, and return theresponse data to the trusted anchor. The trusted anchor can furtherreturn the response data to blockchain 1, thereby completing thecross-blockchain interaction between blockchain 1 and blockchain 2.

In addition to the response data, the trusted attestation conversionrelay can further retrieve corresponding blockchain attestation fromblockchain 2. The trusted attestation conversion relay can verify theresponse data based on the blockchain attestation, for example,determining that the response data exists in a blockchain ledger ofblockchain 2. Implementations are not limited in the presentspecification. In addition, the trusted attestation conversion relay isconfigured with a trusted attestation conversion technology. As such, ifthe result of verifying the response data based on the blockchainattestation is passed, the trusted attestation conversion relay cangenerate a relay attestation based on the trusted attestation conversiontechnology. That is, the blockchain attestation is converted into therelay attestation. Then the trusted attestation conversion relay returnsthe response data and the relay attestation to the trusted anchor. Thetrusted anchor further returns the response data and the relayattestation to blockchain 1. The trusted attestation conversion relaycan publish a root of trust in advance, and blockchain 1 can obtain anddeploy the root of trust in advance. As such, after obtaining theresponse data and the relay attestation, blockchain 1 can verify theresponse data and the relay attestation based on the root of trust so asto determine that the trusted attestation conversion relay has verifiedthe provided response data and the verification is passed.

It can be seen that by using the previous cross-blockchain interactionsystem, both the trusted anchor and the trusted attestation conversionrelay need to be configured with a client device only for a blockchainthat needs to be connected, instead of client devices for allblockchains participating in cross-blockchain interaction. As such, boththe trusted anchor and the trusted attestation conversion relay can bevery lightweight. In addition, different from a relay chain that isbased on a consensus algorithm in an existing technology, the trustedattestation conversion relay is provided with the trusted attestationconversion technology so that the relay can be used to implementsingle-point attestation of reliability of the response data. A processof conversion to the relay attestation is more efficient and convenientthan a consensus process. Therefore, cross-blockchain interactionefficiency can be improved while ensuring reliability of the responsedata. Moreover, the trusted attestation conversion relay obtains onlyone copy of attestation information (that is, the relay attestation), incomparison with multiple copies of attestation information provided byvarious validators in the relay chain in the related technology (whereeach validator provides one copy of attestation information). Thisgreatly simplifies a process of verifying the attestation information byblockchain 1, thereby improving verification efficiency.

The cross-blockchain interaction system based on the previous structuresupports scalable deployment based on actual traffic and capacityrequirements and therefore has very high deployment flexibility. Forexample, FIG. 2 is a schematic structural diagram illustrating across-blockchain interaction system according to an example embodiment.As shown in FIG. 2, multiple trusted attestation conversion relays, forexample, trusted attestation conversion relays 1 to 4, can be deployedin the cross-blockchain interaction system. On the one hand, thequantity of trusted attestation conversion relays can be increased toincrease the quantity of blockchains that can be supported. On the otherhand, each trusted attestation conversion relay can be configured withmultiple types of trusted attestation conversion technologies, forexample, the trusted execution environment (TEE) technology, the proofof authority (POA) technology, and the zero-knowledge proof (ZKP)technology. Implementations are not limited in the presentspecification. Different trusted attestation conversion technologiesimplement different performance models, security boundaries, etc. andtherefore can satisfy application needs in different scenarios.

In some embodiments, trusted attestation conversion relay 1 can beconfigured with the TEE technology, trusted attestation conversion relay2 can be configured with the POA technology, trusted attestationconversion relay 3 can be configured with the MPC technology, andtrusted attestation conversion relay 4 can be configured with the ZKPtechnology. Blockchain 2 and blockchains 4 to 6 can select specifictrusted attestation conversion relays based on actual needs, to performtrusted attestation conversion of blockchain attestations provided bythe blockchains. For example, blockchain 2 can select trustedattestation conversion relays 1 to 3, and then trusted attestationconversion relays 1 to 3 each need to be configured with a client deviceof blockchain 2; blockchain 4 can select trusted attestation conversionrelay 1, and then trusted attestation conversion relay 1 needs to beconfigured with a client device of blockchain 4; blockchain 5 can selecttrusted attestation conversion relays 2 and 4, and then trustedattestation conversion relays 2 and 4 each need to be configured with aclient device of blockchain 5; and blockchain 6 can select trustedattestation conversion relays 2 and 4, and then trusted attestationconversion relays 2 and 4 each need to be configured with a clientdevice of blockchain 6.

In some embodiments, blockchain 2 and blockchains 4 to 6 can sharetrusted attestation conversion relays 1 to 4. In other words, trustedattestation conversion relays 1 to 4 are public relays. This can reducethe quantity of identical trusted attestation conversion relays (thatis, relays configured with the same trusted attestation conversiontechnology) in the cross-blockchain interaction system, therebysimplifying the system complexity. Certainly, the present specificationdoes not limit the configuration of identical trusted attestationconversion relays in the cross-blockchain interaction system. Forexample, when a relatively large quantity of blockchains need to beinvoked, because performance of a single trusted attestation conversionrelay is limited, multiple identical trusted attestation conversionrelays can be configured to implement traffic distribution to satisfythe performance requirement. For another example, identical trustedattestation conversion relays can be configured based on data privacyrequirements. For example, FIG. 3 is a schematic structural diagramillustrating another cross-blockchain interaction system according to anexample embodiment. Assume that trusted attestation conversion relay 1is a public relay and is configured with a TEE technology and thatblockchain expects to use the TEE technology to implement trustedattestation conversion and expects that the response data provided byblockchain 2 not be recorded in trusted attestation conversion relay 1to prevent leakage. Then blockchain 2 can be configured with a privatetrusted attestation conversion relay. The private trusted attestationconversion relay is configured with the TEE technology. In addition, theprivate trusted attestation conversion relay is configured with only aclient device of blockchain 2, and other blockchains cannot (forexample, have no operation permission to) configure their client deviceson the private trusted attestation conversion relay. Therefore, onlyblockchain 2 can use the private trusted attestation conversion relay.

In some embodiments, similar to the relays, trusted anchors can alsoinclude public and private anchors so as to satisfy differentapplication needs. For example, as shown in FIG. 3, blockchain 3 can beconnected to a public trusted anchor. The public trusted anchor can beconfigured with a client device of blockchain 3 so that the publictrusted anchor can monitor a cross-blockchain request on blockchain 3and assist blockchain 3 in obtaining response data provided by otherblockchains. This is similar to the embodiment shown in FIG. 1. Detailsare omitted here for simplicity. Similarly, other blockchains can alsobe connected to the public trusted anchor. Therefore, the public trustedanchor can be configured with client devices of these blockchains andassist these blockchains in completing cross-blockchain interaction.Details are omitted here for simplicity. For another example, blockchain1 can be configured with a private trusted anchor. The private trustedanchor is configured with a client device of blockchain 1, and otherblockchains cannot (for example, have no operation permission to)configure their client devices on the private trusted anchor. Therefore,the private trusted anchor is only used to monitor a cross-blockchainrequest on blockchain 1 and assist blockchain 1 in completingcross-blockchain interaction.

It can be seen that based on the cross-blockchain interaction systemshown in FIG. 3, a blockchain serving as the invoking party can select aprivate trusted anchor or a public trusted anchor based on actual needs,and a blockchain serving as the invoked party can select a privatetrusted attestation conversion relay or a public trusted attestationconversion relay based on actual needs, so as to satisfy privacyrequirements of the blockchain serving as the invoking party or theinvoked party.

It is worthwhile to note that each trusted attestation conversion relayin the present specification can logically be considered as “one device”so that after obtaining cross-blockchain data and a blockchainattestation that are returned by a blockchain serving as the invokedparty, the trusted attestation conversion relay can convert theblockchain attestation into a trusted relay attestation based on averification result of the cross-blockchain data and the blockchainattestation. In addition, there is only one relay attestation, incomparison with multiple attestations provided by multiple validators inthe relay chain in the related technology. Certainly, each trustedattestation conversion relay can actually run on a single electronicdevice, for example, a physical server including an independent host, aPC, a notebook computer, or a cell phone. Or each trusted attestationconversion relay can run on a device cluster that includes multipleelectronic devices, for example, a virtual server running on a hostcluster. Implementations are not limited in the present specification.

FIG. 4 is a schematic structural diagram illustrating still anothercross-blockchain interaction system according to an example embodiment.As shown in FIG. 4, when blockchain 1 selects a private trusted anchor,the private trusted anchor can be connected to public trustedattestation conversion relay 1 and is not necessarily connected to theprivate trusted attestation conversion relay shown in FIG. 3. Inpractice, if blockchain 1 serving as the invoking party has privacyneeds and blockchain 2 serving as the invoked party has no privacyneeds, blockchain 1 can select a private trusted anchor and blockchain 2can select public trusted attestation conversion relay 1 so as tosatisfy the actual needs of each blockchain.

In the embodiments shown in FIG. 1 to FIG. 4, a connection is directlyestablished between a trusted anchor and a trusted attestationconversion relay in the cross-blockchain interaction system. However, inother embodiments, for example, as shown in FIG. 5, which is a schematicstructural diagram illustrating a cross-blockchain interaction systemthat provides a bridging function according to an example embodiment, abridge can be provided. The bridge is separately connected to a trustedanchor and a trusted attestation conversion relay, to bridge the trustedanchor and the trusted attestation conversion relay.

For example, a public bridge is provided and is connected to publictrusted attestation conversion relays such as public trusted attestationconversion relays 1 to 4. The public bridge can be connected to a publictrusted anchor. For example, the public trusted anchor can be directlyconfigured on the public bridge. Certainly, Implementations are notlimited in the present specification. Alternatively, the public bridgecan be connected to private trusted anchor 1 or other private trustedanchors. Then, when blockchain A1 is connected to the public trustedanchor, and blockchains B1 to B4 are separately connected to the publictrusted attestation conversion relays, blockchain A1 can implementcross-blockchain interaction with blockchains B1 to B4. When blockchainA2 is connected to private trusted anchor 1 and blockchains B1 to B4 areseparately connected to the public trusted attestation conversionrelays, blockchain A2 can implement cross-blockchain interaction withblockchains B1 to B4.

For another example, a private bridge is provided and is separatelyconnected to private trusted anchor 2 and private trusted attestationconversion relays 1 and 2. When blockchain A3 is connected to privatetrusted anchor 2 and blockchain B5 is connected to private trustedattestation conversion relays 1 and 2, blockchain A3 can implementcross-blockchain interaction with blockchain B5.

Certainly, as described above, bridges such as the public bridge and theprivate bridge are non-essential. For example, private trusted anchor 1can be directly connected to public trusted attestation conversion relay4, private trusted anchor 2 can be directly connected to private trustedattestation conversion relay 2, and the public trusted anchor can alsobe directly connected to specified public or private trusted attestationconversion relays, to implement cross-blockchain interaction betweenrelated blockchains.

Although bridges are categorized into public bridges and private bridgesin the previous embodiments, in practice, bridges alternatively do nothave to be categorized. For example, a blockchain can be separatelyconnected to a public trusted anchor, a private trusted anchor, a publictrusted attestation conversion relay, and a private trusted attestationconversion relay through the same bridge, provided that thecorresponding bridging function can be implemented. Certainly, ablockchain with relatively high data privacy requirements can choose touse a detected bridge, which is equivalent to the previous privatebridge.

In summary, the present specification proposes the new cross-blockchaininteraction systems. In such systems, blockchains are connected tostandalone trusted attestation conversion relays instead of acentralized relay chain. As such, the systems are not only morelightweight and also support flexible deployment of trusted attestationconversion relays based on traffic and capacity needs. In addition,specific trusted attestation conversion technologies can be selected andconfigured based on actual needs without being limited to methods suchas consensus algorithms. Moreover, blockchains can be configured withpublic or private trusted anchors, trusted attestation conversionrelays, and bridges. The related public nodes can satisfy rapidconfiguration of public blockchains. The related private nodes canprevent privacy data from being obtained by other blockchains, satisfythe privacy requirements of some blockchains, and satisfy theapplication needs of private blockchains or consortium blockchains withaccess permissions.

The system, apparatus, module, or unit illustrated in the previousembodiments can be implemented by using a computer chip or an entity, orcan be implemented by using a product having a certain function. Atypical implementation device is a computer, and the computer can be apersonal computer, a laptop computer, a cellular phone, a camera phone,a smartphone, a personal digital assistant, a media player, a navigationdevice, an email receiving and sending device, a game console, a tabletcomputer, a wearable device, or any combination of these devices.

In a typical configuration, a computer includes one or more processors(CPU), an input/output interface, a network interface, and a memory.

The memory can include a non-persistent memory, a random access memory(RAM), a non-volatile memory, and/or another form that are in a computerreadable medium, for example, a read-only memory (ROM) or a flash memory(flash RAM). The memory is an example of the computer readable medium.

The computer readable medium includes persistent, non-persistent,movable, and unmovable media that can store information by using anymethod or technology. The information can be a computer readableinstruction, a data structure, a program module, or other data. Examplesof a computer storage medium include but are not limited to a phasechange RAM (PRAM), a static RAM (SRAM), a dynamic RAM (DRAM), a RAM ofanother type, a ROM, an electrically erasable programmable ROM (EEPROM),a flash memory or another memory technology, a compact disc ROM(CD-ROM), a digital versatile disc (DVD) or another optical storage, acassette tape, a magnetic disk storage, a quantum memory, a storagemedium based on grapheme, another magnetic storage device, or any othernon-transmission medium. The computer storage medium can be used tostore information that can be accessed by a computing device. Based onthe definition in the present specification, the computer readablemedium does not include transitory computer readable media such as amodulated data signal and carrier.

It is worthwhile to further note that, the terms “include”, “contain”,or their any other variants are intended to cover a non-exclusiveinclusion, so a process, a method, a product, or a device that includesa list of elements not only includes those elements but also includesother elements which are not expressly listed, or further includeselements inherent to such process, method, product, or device. Withoutmore constraints, an element preceded by “includes a . . . ” does notpreclude the existence of additional identical elements in the process,method, product, or device that includes the element.

Specific embodiments of the present specification are described above.Other embodiments fall within the scope of the appended claims. In somesituations, the actions or steps described in the claims can beperformed in an order different from the order in the embodiments andthe desired results can still be achieved. In addition, the processdepicted in the accompanying drawings does not necessarily need aparticular execution order to achieve the desired results. In someembodiments, multi-tasking and concurrent processing is feasible or canbe advantageous.

Terms used in one or more embodiments of the present specification aremerely used to describe specific embodiments, and are not intended tolimit the one or more embodiments of the present specification. Theterms “a” and “the” of singular forms used in one or more embodiments ofthe present specification and the appended claims are also intended toinclude plural forms, unless otherwise specified in the context clearly.It should be further understood that the term “and/or” used in thepresent specification indicates and includes any or all possiblecombinations of one or more associated listed items.

It should be understood that although terms “first”, “second”, “third”,etc. can be used in one or more embodiments of the present specificationto describe various types of information, the information is not limitedto these terms. These terms are only used to differentiate betweeninformation of the same type. For example, without departing from thescope of one or more embodiments of the present specification, firstinformation can also be referred to as second information, andsimilarly, the second information can also be referred to as the firstinformation. Depending on the context, for example, the word “if” usedhere can be explained as “while”, “when”, or “in response todetermining”.

The previous descriptions are only example embodiments of one or moreembodiments of the present specification, but are not intended to limitthe one or more embodiments of the present specification. Anymodification, equivalent replacement, improvement, etc. made withoutdeparting from the spirit and principle of the one or more embodimentsof the present specification shall fall within the protection scope ofthe one or more embodiments of the present specification.

1-20. (canceled)
 21. A cross-blockchain interaction method, comprising:detecting, by one or more relay devices of a cross-chain interactionsystem, a cross-blockchain request sent from a first blockchain network;initiating, by the one or more relay devices, a request to a secondblockchain network in response to detecting the cross-blockchainrequest, wherein the one or more relay devices comprise a second clientterminal associated with a second blockchain network that monitorscross-blockchain requests intended for the second blockchain network;receiving, by the one or more relay devices, a response and a blockchainattestation sent from the second blockchain network; verifying, by theone or more relay devices, the response based on the blockchainattestation; converting, by the one or more relay devices, theblockchain attestation into a relay attestation using a trustedattestation conversion technology after the response is verified; andsending, by the one or more relay devices, the response and the relayattestation to the first blockchain network.
 22. The cross-blockchaininteraction method of claim 21, wherein detecting, by the one or morerelay devices of the cross-chain interaction system, thecross-blockchain request sent from the first blockchain networkcomprises: detecting, by the one or more relay devices of thecross-chain interaction system, the cross-blockchain request sent fromthe first blockchain network through one or more anchor devices, whereinthe one or more anchor devices comprises a first client terminalassociated with the first blockchain network, and wherein the firstclient terminal is configured to monitor cross-blockchain requests sentfrom the first blockchain network.
 23. The cross-blockchain interactionmethod of claim 21, wherein the one or more relay devices comprises aplurality of relay devices and wherein two or more relay devices in theplurality of relay devices generate relay attestations based ondifferent trusted attestation conversion technologies.
 24. Thecross-blockchain interaction method of claim 22, wherein detecting, bythe one or more relay devices of the cross-chain interaction system, thecross-blockchain request sent from the first blockchain networkcomprises: detecting, by the one or more relay devices of thecross-chain interaction system, the cross-blockchain request sent fromthe first blockchain network through the one or more anchor devices. 25.The cross-blockchain interaction method of claim 22, wherein detecting,by the one or more relay devices of the cross-chain interaction system,the cross-blockchain request sent from the first blockchain networkcomprises: detecting, by the one or more relay devices of thecross-chain interaction system, the cross-blockchain request sent fromthe first blockchain network through the one or more anchor devices anda bridge device connecting the one or more anchor devices and the one ormore relay devices.
 26. The cross-blockchain interaction method of claim25, wherein the bridge device comprises at least one private bridgedevice for cross-blockchain communications between the first blockchainnetwork and the second blockchain network.
 27. The cross-blockchaininteraction method of claim 25, wherein the bridge device is coupled toand in two-way communication with the one or more anchor devices and theone or more relay devices.
 28. The cross-blockchain interaction methodof claim 22, wherein the first client terminal is configured to performsimplified payment verification (SPV) on a first blockchain associatedwith the first blockchain network, and the at least one of the one ormore relay devices is configured to perform SPV on a second blockchainassociated with second blockchain network.
 29. The cross-blockchaininteraction method of claim 21, wherein the trusted attestationconversion technology comprises one or more of a trusted executionenvironment (TEE) technology, a proof of authority (POA) technology, asecure multi-party computation technology, or a zero-knowledge proof(ZKP) technology.
 30. The cross-blockchain interaction method of claim21, wherein a root of trust of the one or more relay devices ispre-recorded on a blockchain to be used by blockchain nodes of the firstblockchain network to verify the response and the relay attestation. 31.A cross-blockchain interaction system, comprising: one or more relaydevices, wherein at least one of the one or more relay devices comprisesa client terminal associated with a second blockchain network thatmonitors cross-blockchain requests intended for the second blockchainnetwork, wherein the at least one of the one or more relay devices isconfigured to perform operations comprising: receiving, by the one ormore relay devices, a response and a blockchain attestation sent from afirst blockchain network; verifying, by the one or more relay devices,the response based on the blockchain attestation; converting, by the oneor more relay devices, the blockchain attestation into a relayattestation using a trusted attestation conversion technology after theresponse is verified; and sending, by the one or more relay devices, theresponse and the relay attestation to the first blockchain network. 32.The cross-blockchain interaction system of claim 31, wherein detecting,by the one or more relay devices of the cross-chain interaction system,the cross-blockchain request sent from the first blockchain networkcomprises: detecting, by the one or more relay devices of thecross-chain interaction system, the cross-blockchain request sent fromthe first blockchain network through one or more anchor devices, whereinthe one or more anchor devices comprises a first client terminalassociated with the first blockchain network, and wherein the firstclient terminal is configured to monitor cross-blockchain requests sentfrom the first blockchain network.
 33. The cross-blockchain interactionsystem of claim 31, wherein the one or more relay devices comprise aplurality of relay devices and wherein two or more relay devices in theplurality of relay devices generate relay attestations based ondifferent trusted attestation conversion technologies.
 34. Thecross-blockchain interaction system of claim 32, wherein detecting, bythe one or more relay devices of the cross-chain interaction system, thecross-blockchain request sent from the first blockchain networkcomprises: detecting, by the one or more relay devices of thecross-chain interaction system, the cross-blockchain request sent fromthe first blockchain network through the one or more anchor devices. 35.The cross-blockchain interaction system of claim 32, wherein detecting,by the one or more relay devices of the cross-chain interaction system,the cross-blockchain request sent from the first blockchain networkcomprises: detecting, by the one or more relay devices of thecross-chain interaction system, the cross-blockchain request sent fromthe first blockchain network through the one or more anchor devices anda bridge device connecting the one or more anchor devices and the one ormore relay devices.
 36. The cross-blockchain interaction system of claim35, wherein the bridge device is coupled to and in two-way communicationwith the one or more anchor devices and the one or more relay devices.37. The cross-blockchain interaction system of claim 32, wherein thefirst client terminal is configured to perform simplified paymentverification (SPV) on a first blockchain associated with the firstblockchain network, and the at least one of the one or more relaydevices is configured to perform SPV on a second blockchain associatedwith second blockchain network.
 38. The cross-blockchain interactionsystem of claim 31, wherein the trusted attestation conversiontechnology comprises one or more of a trusted execution environment(TEE) technology, a proof of authority (POA) technology, a securemulti-party computation technology, or a zero-knowledge proof (ZKP)technology.
 39. The cross-blockchain interaction system of claim 31,wherein a root of trust of the one or more relay devices is pre-recordedon a blockchain to be used by blockchain nodes of the first blockchainnetwork to verify the response and the relay attestation.
 40. Anon-transitory, computer-readable medium storing one or moreinstructions executable by a computer system to perform operationscomprising: detecting, by one or more relay devices of a cross-chaininteraction system, a cross-blockchain request sent from a firstblockchain network; initiating, by the one or more relay devices, arequest to a second blockchain network in response to detecting thecross-blockchain request, wherein the one or more relay devices comprisea second client terminal associated with a second blockchain networkthat monitors cross-blockchain requests intended for the secondblockchain network; receiving, by the one or more relay devices, aresponse and a blockchain attestation sent from the second blockchainnetwork; verifying, by the one or more relay devices, the response basedon the blockchain attestation; converting, by the one or more relaydevices, the blockchain attestation into a relay attestation using atrusted attestation conversion technology after the response isverified; and sending, by the one or more relay devices, the responseand the relay attestation to the first blockchain network.